Inspect any file's real type by its binary signature (not just its extension), size, SHA-256/MD5 hashes, and basic details.
Frequently asked questions
It means the file's actual binary signature doesn't match what its extension or upload content-type suggests — for example, a file renamed from .exe to .jpg. This is a useful quick check before trusting an unfamiliar file.
Common formats identifiable by their binary signature — images, archives, PDFs, and more. Unrecognized formats will simply show as unknown.